I believe that the xinetd "includedir" operator should probably ignore
files whose names end in "~" and other files that are commonly ignored by
such things.

Furthermore, it should skip over subdirectories.  I RCS all the config
files that I modified, so I created the /etc/xinetd.d/RCS directory and
checked some files in before editing, and when xinetd starts up it
complains about being unable to read the configuration file
/etc/xinetd.d/RCS.